The P-38 Lightning was the first military aircraft designed by Lockheed. It was to meet a 1937 specification for a high altitude interceptor that could fly at 20,000' at 360 mph and at 1,500' at 290 mph. The ascent of the plane was to take only six minutes. Many of the aircraft companies of the time thought it was impossible to meet the specification.
H. L. Hibbard and Clarence "Kelly" Johnson, Lockheed's head designers, chose a design with two engine that would have supercharges placed in the tails. Radiators and landing gear were to be located in the tails as well. The design was to have a 23 mm cannon and four machine guns placed in the nose in front of the pilot.
Some pilots complained that in the early models the cockpit was very uncomfortable. At high altitudes some pilots even got frostbit.
On many of the models the nose held a 20 mm cannon and four .50 cal machine guns providing a powerful punch.
The Allison engines were sometimes prone to over heat.
The engines had the radiators in the twin booms which gave excellent high-altitude performance.
To eliminate some of the problems of torque in two engine aircraft, the engines were designed to rotate in opposite directions.
The tricycle undercarriage made the P-38 Lightning easier to land and made the engines easier to maintain.
The P-38D Lightning was the first production version.
The Lockheed P-38D Lightning had self sealing fuel tanks and armor protection for the pilot.
The tail system was modified for better control.
The Lockheed P-38F Lightning had more powerful engines and could carry ordnance or drop tanks in pylons under the wings which were strenghthened.
The cockpit was rear hinged and opened upwards.
The Allison engines were rated at 1,425 HP but were restricted to 1,240 HP. There were cooling problems with the engine.
Due to cooling problems in previous version of the P-38, the P-38J had a reorganized cooling and turbo charger intercooling systems. The nacelles had a different shape and deeper intakes.
The dive brakes on the P-39J were electrically controlled.
The engines were no longer limited. Emergency boost was 1,600 HP.
The P-38Ls could carry 10 HVAR 5" rockets in trees that were located under the wings.
The basic Lockheed F-4 Lightning was a standard P-38 with the weapons being removed from the nose and putting a clear nose in with cameras.
The first F-5A flew in September 1942.